Created attachment 604844 [details]
Error msg page when enable jenkins build.

Description of problem:
    After I created a application named "py", I tried to "Enable jenkins build" to it , but caughted error mistake: "Cartridge Could not add job "py-build" in jenkins server:create_job status:503 You'll need to correct this error before attemping to embed the Jenkins client again" , as the attachment show.
    If I tried again later by clicked "add jenkins" button in this error page, it will be added successful.
    This issue is probably caused by the too long time to prepare jenkins server.But the error message seems not clear to user. There should be a message to tell user what the problem is and guide user to wait a seconds to try again.

Version-Release number of selected component (if applicable):
devenv_1997

How reproducible:
always

Steps to Reproduce:
1.Create an application.
2.Tried to "Enable jenkins build" to it.
3.
  
Actual results:
Get error message which seems not clear to user. 

Expected results:
It should be added successful or give a more clear message to guide user waiting a minute to try again.

Additional info: